Hershey bar wing vs composite wing - how much drag?

("Wayne Paul" wrote)
It is much easier to build a laminar flow airfoil and complex shaped
wing to fuselage transition using composite construction. These wing have
a better lift to drag ratio. The decrease in drag aerodynamic drag of
the wing and static drag decrease associated with the wing/fuselage
transition allow faster speeds.


Can you reword this (for some of us "Huh?" lurkers) especially the wing to
fuselage transition part?

How good/efficient are Cherokee, Ercoupe, Cessna (aluminum & rivet) wing
root fairings vs. what could be achieved with complex composite shapes?

Same question with the wing shape - to hold up the same plane, ALL else
being equal?

So ballpark - how much more efficient would the use of complex composite
construction (wings and wing root transition areas) make these planes - ALL
else being equal?

WAG - same power, weight, fuselage, etc - what improvements would these
planes see in speed, climb, stall, or fuel burn numbers?

Thanks.


Montblack

"Montblack" wrote in message
...
("Wayne Paul" wrote)
It is much easier to build a laminar flow airfoil and complex shaped
wing to fuselage transition using composite construction. These wing
have a better lift to drag ratio. The decrease in drag aerodynamic drag
of the wing and static drag decrease associated with the wing/fuselage
transition allow faster speeds.


Can you reword this (for some of us "Huh?" lurkers) especially the wing to
fuselage transition part?

How good/efficient are Cherokee, Ercoupe, Cessna (aluminum & rivet) wing
root fairings vs. what could be achieved with complex composite shapes?

Same question with the wing shape - to hold up the same plane, ALL else
being equal?

So ballpark - how much more efficient would the use of complex composite
construction (wings and wing root transition areas) make these planes -
ALL else being equal?

WAG - same power, weight, fuselage, etc - what improvements would these
planes see in speed, climb, stall, or fuel burn numbers?

Thanks.


Montblack

Let me make this as simple as possible by simply giving you an example. My
HP-14 (http://www.soaridaho.com/Schreder/N990_Borah_Mt.JPG) has a 52 foot
wingspan. The wings were built with flush rivets and have been smoothed by
adding an epoxy/balloon mixture. This is mid 1960 construction techniques
using aluminum construction. My lift to drag ratio is around 36 to 1.
However, new modern sailplanes with composite construction and modern
airfoils that only have 15 meter (just under 50 feet) wingspan have glide
ratios of around 48 to 1.

So with both of my old HP-14 and an ASW-27 (http://tinyurl.com/8lecz) loaded
to have a gross weight of 800 lbs. At best glide speed my HP-14 would have
about 22 lbs of drag while the ASW-27 would have less then 17 lbs of drag..
So the ASW-27 is 30% more efficient then my 14. If my wings did not have
flush rivets and were not smoothed the difference would be even greater.

The same is true with power aircraft. Just compare the Flight Design CT
(http://www.flightdesignusa.com/) with a Cessna 152 or a Cirrus with any
earlier conventionally constructed aircraft of similar weight and
horsepower.

To take these in steps, the wing is the most important, the fuselage shape
is also important and the junction between the wing and fuselage. I am
familiar with a smooth wing metal sailplane that was re-winged with a modern
airfoil. The new wing, has the same area and span. The original
wing/fuselage combination produced a 38 to 1 glide ratio. The updated
combination produced a 42 to 1 glide ratio. That is a 10 percent
improvement. Going from a round riveted wing to a modern airfoil should
provide a 15+% improvement.

Wayne
HP-14 "6F"

In article ,
"Montblack" wrote:

("Wayne Paul" wrote)
It is much easier to build a laminar flow airfoil and complex shaped
wing to fuselage transition using composite construction. These wing have
a better lift to drag ratio. The decrease in drag aerodynamic drag of
the wing and static drag decrease associated with the wing/fuselage
transition allow faster speeds.


Can you reword this (for some of us "Huh?" lurkers) especially the wing to
fuselage transition part?

How good/efficient are Cherokee, Ercoupe, Cessna (aluminum & rivet) wing
root fairings vs. what could be achieved with complex composite shapes?

Same question with the wing shape - to hold up the same plane, ALL else
being equal?

So ballpark - how much more efficient would the use of complex composite
construction (wings and wing root transition areas) make these planes - ALL
else being equal?

Paul,
Go to airliners.com or any other site that will have "new" and "old"
airplanes. Pay particular attention to the wing-fuselage junction.
On the old airplanes, the fuselage seems to be just stuck to the wing.
On the new aiplanes, there are HUGE fillets fore and aft of the wing.
This really became a design consideration in the mid-1980's.

("john smith" wrote)
On the new aiplanes, there are HUGE fillets fore and aft of the wing. This
really became a design consideration in the mid-1980's.


Wheel pants, gap seals, ....and HUGE new fiberglass fillets (fore and aft).
Are they part of everyday speed-mod packages?

If so, what is the "anecdotal" gain, after installing (just) them?

I've read reports on wheel pants, on gap seals, and on Power Flow exhaust
systems, but not on aftermarket fillets for the GA fleet.

http://www.powerflowsystems.com/


Montblack
airliners ...net? :-)

On Wed, 28 Mar 2007 23:11:29 -0500, "Montblack"
wrote:

("john smith" wrote)
On the new aiplanes, there are HUGE fillets fore and aft of the wing. This
really became a design consideration in the mid-1980's.


Wheel pants, gap seals, ....and HUGE new fiberglass fillets (fore and aft).
Are they part of everyday speed-mod packages?

If so, what is the "anecdotal" gain, after installing (just) them?

I've read reports on wheel pants, on gap seals, and on Power Flow exhaust
systems, but not on aftermarket fillets for the GA fleet.

http://www.powerflowsystems.com/

Knots2U sells a wing/fuselage fairing.

http://knots2u.com/28WR.htm

I have it on my Cherokee, but cannot discern the exact performance
gain as it was added in conjunction with a number of other mods.